Grinding machine



June 30, 1936. w, B1NN$ 2,045,894

GRINDING MACHINE Filed Dec. 2, 1931 6 Sheets-Sheet l June 30, 1936. G w, BlNNs 2,045,894

GRINDING MACHINE Filed Dec. 2, 1931 6 Sheets-Sheet 2 Zhwentor Ottorng June 30, 1936. G. w. BINNS 2,045,894

GRINDING MACHINE Filed Dec. 2, 1931 6 Sheets-Sheet 3 Snuentor June 30, 1936. G. W. BINNS GRINDING MACHINE 6 SheetsSheet 4 Filed Dec. 2, 1931 I Zhmentor fafiaz/ w attorney 6 Sheets-Sheet 6 G. W. BINNS GRINDING MACHINE June 30, 1936.

Filed Dec. 2, 1951 I ence to the accompanying drawings illustrating this invention may comprise a bed It having ris- '-ing therefrom at one end thereof the pedestal Patented June 30,1936

* GRINDING MACHINE George W. Binns, Cincinnati, Ohio, assignor to Cincinnati Grinders Incorporated, Cincinnati, Ohio. a. corporation of Ohio Application December 2, 1931, Serial'No. 578,539 18 Claims. ((71. 51-103) This invention relates to improvements inmachine tools and especially to improvements in a grinding machine.

An object of the invention is the provision of a grinding machine for efiecting an intermittent contact between the work and grinding wheel for spot grinding around the-periphery of a cylindricai article.

Another abject oi the invention is the provision of a grinding machine for variably relieving or under-cutting sides of cylindrical articles. Another object of the invention is the provision of a grinding machine for accomplishing the results above set forth sotimed that the relieved or under-cut portions will bear a definite relation to other portions of the work piece. I

' A further object of the invention is the provision of a grinding machine for relieving the skirt of internal combustion enginepistons at definite predetermined points relative to the re-,

mainder of the piston.

A still further object is the provision of a semi-. automatic grinding machine for accomplishing the objects above set forth.

Other objects and advantages of the present invention should be readily apparent by referthe invention taken in connection with the accompanying specification and it is to be understood that any modifications may be made in the exact structural details there shown and described within the scope of the appended claims without departing from or exceeding the spirit of shown in Figures 1 and 2.

the invention.

In the drawings: Figure 1 is a front'elevation of a grinding'machine embodying "improvements of this invention.

Figure 2 is a top plan view of the machin shown in Figure 1. o Figure 3 is an end elevation of the machine Figure 4 is ahorizontal sectional view taken on line H of Figure "1.

Figure 5 is a vertical sectional view taken on line 55 of Figure 4. j

Figure 6 is a sectional view taken on line 6-4 of Figure 4. 'f

Figure 7 is a fragmentaryview'of one of the cams in development. I I

Figure 8 is a sectional view-taken on line l-.-l of Figure 4. a I v Figure 9 is an elevational view of an internal combustion engine piston showing the relieved portions ground by this machine.

Figure 10' is a fragmentaryv top lan View of the machine shown in Figure 1 including certain modifications.

Figure 11 is a sectional view taken on line ll-II ofFigure 1'0.

Figure 12 is a sectional view taken on line Figure 13 is a sectional view taken on line Iii-I3 of Figure 10. I Figure 14 is a diagrammatic view of the hydraulic circuits involved in this invention. Throughout the several views of the drawings similar reference characters are employed to denote the same or similar parts V As'was noted above the principal. object of this invention is the relieving of cylindrical parts at definite points around its external surface.

shown in Figure 9 the work piece I0 is provided with the undercut or relieved portions H and I'2 which are duplicated on oppositesides and lie adjacent the connecting rod wrist pin holes or pads I8. It will be noted that the end ll of the skirt is left cylindrical as well'as the piston ring land portion l5. This intermittent or spot grinding is accomplished by feeding the work toward and from the grinding-wheeltwice during each revoiutionof the work.

A machine for accomplishing the purposes of grinding Iwhe'el may be properly conditioned or and from the grinding wheel i8. In order to ad- 'Just the carriage 23 relative to the ways 22 it has secured therein a sleeve nut 24 held against movement relative tothe carriage by means of a nut Jflf-threaded thereon. Meshing-with the v threadspf the-sleeve nut 24 are the threads 26 mechanism 2| whereby the active face of the ,formed. I6 is further provided on its upper surface wit h guideways 22 for guiding the carriage-.23 longitudinally oi'the bed l6 toward of an adjusting screw 21 journaled in a bracket 28 secured in any desirable manner to an exten slon 2a of the bed l6. Secured to the screw :1

"beyond the bracket 28 is a pilot or hand wheel 30 whereby the saidscrew may be actuated.

The'carriage 23 is provided within its perlph Y era! bounds with bosses 3| and 32 in which is Journaled a stud 33. The stud 33 lies above: an

opening 34 in the carriage 23 ,which opening is beyond the rear wall of the bed IS. The bed l5 incloses a change speed or gear box 35 'which terminates in a shaft 35 projecting exteriorly of the machine. The initial power may be derived from any suitable source such as the counter shaft, individual motor or the like for ro tating the shaft 35 at the desired speed depending upon the adjustment or engagement of the transmission gears within the speed box 35. Secured to the shaft 35 is a sprocket 31 about which -is trained a sprocket chain '38 which is also drive shaft 43 journaled in the slide and from which the power or motion is taken for operating the several parts about to be described.

From the foregoing it will be noted that the sprocket 39 may be operated at various speeds for rotating the driven shaft 43 so that the several parts controlled thereby are operated at different desirable speeds depending entirely on the work being operated upon as well as on the desires or wishes of the operator.

In order to efiect the rotation of drive shaft 43 the'bevel pinion or gear 4| is provided on its rear surface with clutch teeth v 44 adapted to mesh with complementary clutch teeth 45 formed on the adjacent end of slidable clutch member 45 keyed or otherwise slidably connected as at 41 with the driven shaft 43. The clutch member 45 is provided with a counter-bore 48 in which is received a spring 49 abutting on one end with the base of the counter-bore and on the other end with a collar 50 pinned or otherwise secured to the shaft".

.As illustrated in Figure 4, the clutch teeth 44 and 45 are in contact with one another whereby nected to the work driving shaft section 55 which has on its forward end a work driving head 51. This head 51 asshown in the drawings is of a width to fit between the opposed faces of the wrist pin lugs-l3 and effect a driving connection with the piston or work l8 thereby. The head 51 is further provided with an adjustable screw or bolt 58 forming a stop for limiting the movement of the piston or the head 51 by engaging the inner surface of the piston head. The head 51 is provided on its longitudinal sides with springs 51-A to take up any play between the said head and the work as well as permit a slight relative movement between the work and head when desired.

The work or piston I8 is supported during the grinding operation by a roll 59 journaled at its opposite ends in a forked frame 50 pivoted at 5| to lugs 52 carried by the carriage 23. The arms 53 and 54 of the frame 55 flank the sides of grinding wheel l8 and each has pivoted thereto as at 55 9. two-fingered arm 55. Each of the fingers of the arm 55 carries a roller 51 adapted to engage the cylindrical portions 4 and I5 of the piston. A roller 58 carried by the fork 59 of a'plunger head 18 engages the work In at a point above center and on the opposite sides to that which contacts with the grinding wheel l8. By reference to Figure 5 the position of the several rollers will be readily perceived. From this it will .be seen that the roller 59 is in a position to take the thrust of the grinding wheel as it removes the stock from the piston and the said roller 59 acts as a work rest or support. The roller 58 effects the lateral shifting of the work toward the grinding wheel and maintains contact between the work and work supporting roller 59 as well as the guide rollers 51 but yields during the lateral shifting of the work as will later appear.

The pressure roller 58 and its supporting head 18 are secured to or made integral with a plunger 1| slidably mounted in a bearing sleeve 12 rising from. the carriage 23. The plunger 1| has formed therein a bore 13 receiving the forward portion of a sliding rod 14. The plunger 1| is provided ahead of the bore 13 with a counter-bore 15 of a diameter less than the diameter of the bore 13.

In axial alignment with the relatively small di-' ameter bore 15 the rod 14 is provided with a counter-bore 15 of the same diameter as the bore 15. Received in the bores or sockets '15 and 15' is a coiled spring 11 abutting on the opposed bases of said sockets and affording a. yieldable connection between the slide rod 14 and plunger 1|. The slide rod 14 is provided intermediate its ends with a slot 18 through which a pin 19 extends. The pin being carried by the plunger,

1| so that after a limited movement of the rod 14 in either direction the plunger 1| is actuated thereby. This rod 14 carries at its rear end a pin 88 having on the end thereof a roller 8| received in a cam groove 82 of a barrel cam 83 ,secured to shaft 84 j'ournaled in bearings pro a clockwise direction through substantially at which time the lever 85 stands in a substantially, vertical position. It is desired that shaft 43 and all parts operated therefrom be stopped when the work piece is being replaced on the work driving head 51. For this reason the connecting and disconnecting clutch 45 is operated bythe hand lever 85. This control mechanism comprises a cam 85, see Figure 6, keyed or otherwise secured to the other end of the shaft 84. The cam 85 is provided with an interrupted periphery as shown at 81 which cooperates with the nose 88 of a rod 89 adapted to be axially shifted laterally or the carriage 23. The other end of the rod 89 is provided with a notch- 60 receiving the ball end 9| of a link 92 pivoted intermediate its end to a vertical stud 93 carried by the carriage 23. The link 92 is provided on its other end with a ball portion 94 receiving in a notch 95 formed in a plunger 95. The plunger 05 and as will be noted therein is provided on its 75 2,045,894 one end with an offset portion I02. The offsetportion I02 is such that when the nose I of plunger 96 is within the groove it effects a shift ing of the clutch member 46 to the right as seen in Figure 4 for disengaging the clutch teeth 44 and 45. It will further'be noted that the cam groove IOI terminates in a vertical wall I03 which when engaged by the nose I80 of the plunger 96 4 stops further coasting or rotation of the clutch .me journaled in suitable bearings provided by the carriage 2a. The stud I05 has secured to its other end a cam I06, see Figure 8, having diametrically opposed high portions I01 and I08 joined by diametrically opposed low portions I09 and I I0. The carriage 23 is provided beneath the cam I06 with a boss III for a guide sleeve II2 through which is axially shifted a plunger 3. The plunger II 3 has rotatably journaled on its upper end a roller H4 adapted to contact with the periphery of the cam I06; .The other end of v the plunger II3 has pivoted at II5 one end of an arm II6 which is keyed or otherwise secured at its other end to the pivot shaft 6| of the forked frame 60. The rotation'of the cam I06 effects the oscillation or rocking movement of the work controlling frame 60 for retracting the work periodically from the grinding wheel against the resistance of the plunger feed spring II which causes the work to feed toward the grinding wheel as the low spots of the cam I06 with the plunger I I3. g

At 'the conclusion of the grinding operation when the handle or lever 85 is oscillated in a clockwise direction, the cam groove 82 retracts the slide rod I4 pulling with it the plunger II. This plunger II as noted above, carries the head register I0 for the pressure roller 68 which head 'I0\.has

extending beyond it the shaft or stud I II of the roller-68 which is positioned within the space I I 8 formed by arms H9 and I20, see Figure 8. These arms II9 and I20 are integral with the arm I H of a bell crank I22 which is pivoted at I23 to the carriage 23. At the junction of the arms of the bell crank I22, it is provided with an enlarged bore I24 through which passes the section 56 of the work driving shaft. From this it will be seen that as the rod I4 is retracted it carries with it the plunger II and through the roller shaft extension III andarm IZI oscillates the workdriving shaft section 56 about the universal joint 55 for properly positioning the said shaft for work removal and insertion relative to the driving head 51. i.

The complete operationof the machine is as follows:

With the parts in a retracted position a work piece is mounted on the driving head 51 with the sides thereof engaging the opposed faces. of

clockwise direction and shift the rod 89 to the right as seen in Figure 6. This oscillation of the link. 92 retracts the plunger 96 withdrawing its nose I00 from the cam groove IOI in the clutch member 46. This release of the clutch 46 permits the spring .49. to expand and effect a'driving engagement between the clutch teeth 44 and 45. Since the sprocket 39 is being constantly rotated, the shaft 43 will immediately rotate after engagement of the clutch teeth. The rotation of 'the shaft 43 causes through the inter-meshing of pinions 52and 53 the rotation of the work I0. Simultaneously with the rotation of the work I0 the cam I06 is rotated through the bevel gears or pinions-5I and I04 for oscillating the arm H6 and effecting the feed and retraction of the work relative to the grinding wheel. It will be seen that the parts are so inter-coupled that the work makes two feeding and retracting movements toward and from the grinding wheel for each rotation thereof since the cam I06 is rotated at the same speed as the work and sinceit is provided with a double throw spaced 180 apart for synchronizing the said movement of the work toward and from the wheel with its rotation.

The modified machine shown in Figures 10 to 14 inclusive illustrates a power controlled mechanism requiring only so much of the attention ing a hydraulic control valve. The driven shaft 43 is extended through and beyond the end bearing of the carriage 23 as shown at I in Figure 10. A pinion I3I is secured to the end of the shaft extension I30 and meshes with a large gear I32 loosely joumaled on a stud I33 driven into or secured to a boss I34 on the carriage 23. The only other change from'the mechanism above described is the replacement of the handle 85 on the cam shaft 84 by a rack pinion I35 which meshes with a rack I36 secured to or formed on a piston rod I31. The piston rod I3I is carried by an hydraulically actuated piston I38 inclosed within a cylinder I39 secured by a bracket I40 to the upper surface of the slide 23. The piston of the operator as is necessary to initiate the automatic operation thereof by manually shiftrod I3I is extended beyond the rack I36 and forms a pilot or guide I4I slidable through an aperture formed in a bracket I42 secured to the forward face of the carriage 23.

Mounted on the upper surface of the carriag ports I49 and I50 respectively connecting with a pressure source and reserve tank by means of conduits I5I and I 52 extending therefrom. The valve casing is further provided with ports I53 and I54 respectively connected as by conduits I55 and I56 with the opposite ends of the piston cylinder I39.- The pressure port I49 communicates with a port 151 which is controlled by a throttle valve I58 and connects with alongitudinal port I59 communicating at its opposite ends through. ports I 60 and I6I with the interior of the valve casing I40. The pressure from the port I 60 is directed by the valve spool into the conduit I55 for actuating the piston I38 in one direction and the exhaust fluid behind the piston is ex-'.

hausted through the conduit I56 and spool valve to the exhaust port and conduit I50 and I52. When the spool valve I45 is shifted to itsother position the pressure from the port I6I is then directed by the spool valve'to the conduit I56. for

which time the exhaust is had from the cylinder through the conduit I55, valve I45 to the con- .duit I52.

It will be understood that actuation of the piston to the right as seen in Figure 11 effects the operation of the parts in the same manner that the oscillation of the lever 85 from a vertical position to a horizontal position and that a reverse movement of the piston retracts the parts to their initial positions.

The valve I45 is actuated by means of a lever I52 which is secured in a pivoted stud I53 and has on its one end the knob I54. The lever I52 has a shoe depending from it received in the annular groove I43 of valve stem head I41 and its other end in the bifurcated end I55 of a lever I55., The lever I55 is pivoted at I51 to a boss I58 extending outwardly from the carriage 23. The other end of the lever I55 is also bifurcated as at I59 and has rotatably journaled therein roller I10. The roller I18 is adapted to be engaged, for oscillating the lever I55, by a stud I1I' projecting from the side of the large gear32.

In the lug I58 nearest the forked end I55 of f the lever there is provided a socket I12 in which is mounted a detent I13 actuated outwardly by means of a spring I14 abutting on one end with the base of the socket I12 and on the otherend with the under side of the detent I13. The lever I55 is provided with a socket I15 on its under surface and adapted to receive the detent I13 for holding the lever in one position against the yielding resistance of a spring I15 secured at one end to the lever I55 and anchored at its other end I11 to the carriage 23.

The operation of the power actuated mecha nism is as follows: After placing a work piece on the driving head 51 the operator actuates the valve handle 152 in a clockwise direction as seen in Figure 10. This'shifts the valve I45 inwardly and through the end of the handle I52 oscillates the arm I55 in a counter-clockwise direction. This movement of the .valve lever I 52 initiates movement of the piston I38 for rotating the rack pinion I and thereby setting in motion the various parts of the mechanism. The initiation or rotation of the shaft 43 also rotates the pinion I3I which is meshed with the gear I32. As shown in the drawings a ratio of eight to one exists between the gear I32 and pinion I3I whereby the shaft 43 will make eight revolutions to one revolution of the gear I32. At this time the spring pressed detent I13 is holding the valve lever I52 in its operative position. As soon as the gear I32 makes a complete revolution, the stud I1I thereon engages the roller I10 and actuates the arm I55 in a clockwise direction thereby freeing said arm of the restraint placed thereon by the detent I13 whereupon the spring I15 oscillates it in a clockwise direction about the pivot I51 for shifting the valve control lever I52 to its other position causing the hydraulic fluid to be connected with the other side of the piston I38 and effecting its reverse actuation. This reverse movement of the piston I38 is the equivalent of oscillating the handle I85 in a counter-clockwise direction and eflecting the retraction of the parts. As soon as the piston reaches the limit of its rearward movement the clutch is disengaged as above described, thereby stopping furth'er rotation of all the parts pending the manual shifting of the lever I52 rearwardly after the finished work piece has been replaced.

It will be noted that this modification provides 2,045,894 actuating the piston in the other direction, at

the same amount of grinding time for each work piece, thereby insuring successive work pieces being produced in identical conditionand finish.

What is claimed is:

1. In a grinding machine of the class described, 5

the combination of a bed, a grinding wheel rotatably supported thereby, a work rotating and feeding mechanism including a slide mounted on the bed, supporting and pressure rolls on the slide, yielding means for urging the pressure roll 10 in the direction of the work to maintain contact between the work and supporting roll and grinding wheel, and additional power operated means for periodically retracting the work from the grinding wheel against the yielding urge of the 15 ing wheel against the yielding urge of the pressure roll, said power retracting means consisting .of a cam rotated at the same speed as the work for' controlling the engagement of the work and grinding wheel.

3. In a grinding machine for spot grinding the cylindrical surface of a cylindrical work piece the combination of a bed, a grinding wheel rotatably mounted thereon, a power rotated head connected with the work for rotating same, means peripherally supporting the work for rotation while being driven by the head, yielding means urging the work into engagement with its support and the grinding wheel, power means for retracting the work periodically from the grinding wheel against the yielding resistance of pressure means, a power source normally disconnected from the work rotation and work retraction means, a yieldingly actuated clutch for connecting the power source with the said power actuated means, and a lever for connecting and disconnecting the clutch with the power source.

4. In a grinding machine for spot grinding the cylindrical surface of a cylindrical work piece the combination of a bed, a grinding wheel rotatably mounted thereon, a power rotated head connected with the work for rotating. same, means peripherally supporting the work for rotation awhile being driven by -the head, yielding means urging the work into engagement with its support and the grinding wheel, power means for retracting the work periodically from the grinding wheel against the yielding resistance of pressure means, a power source normallydisconnectedfrom 60 the work rotation and work retraction means, a yieldingly actuated clutch for connecting the power source with the said power actuated means, a lever for connecting and disconnecting the clutch with the power source, and means operated 5 by the lever for initially actuating the pressure roll.

5. In a work rotation and feeding mechanism of the class described, the combination of a driven shaft, a 'work driving head connected with the 7 work and driven shaft, a work feeding mechanism connected with the driven shaft, a power source, a clutch yieldingly actuated for connecting the power source with the driven shaft, a cam associated with the clutch, a plunger adapt- 75 ed to cooperate with the cam for retracting same against the yielding urge thereof, means for holding the plunger out of engagement with the cam during the operating cycle, said means compris ing a spring urging the plunger in one direction, a rod, a coupling between the rod and plunger whereby movement of the plunger in one direc-e tion shifts the rod in the reverse direction, and removable means contacting with the rod for limiting its movement and thereby holding the clutch plunger out of engagement with the clutch cam.

. 6. In a work rotation and feeding mechanismof the class described, the combination of a driven shaft, a work driving head connected with the work and driven shaft, a work feeding mechanism connected with the driven shaft, a power source, a clutch yieldingly actuated for connecting the power source with the driven shaft, a cam as--,

sociated with the clutch, a plunger adapted to,

cooperate with the cam for retracting same against the yielding urge thereof, means for holding the plunger out of engagement with the cam during the operating cycle, saidmeans comprising a spring urging the plunger in one direction, a rod, a coupling between the rod and plunger whereby movement of theplunger in one direction shifts the rod in the reverse direction, removable means contacting with the rod for limiting its movement and thereby holding the clutch plunger out of engagement with the clutch cam, and a manually actuable lever for actuating the removable meanslfrom the path of the shiftrod.

7.- In a grinding machineof the class described, the combination of a bed, a grindingwheel rotatably mounted on the bed, a'work supporting member adjacent the grinding wheel for peripherally supporting the work, flexible driving means 7 for rotating the work on the supporting member, yieldably actuated meansincluding a work contacting roll for urging the work into engagement with the supporting member and grinding wheel, means limiting the movement of the work in the direction of the grindingwheel, means for periodically shifting thework from the grinding wheel to eflect spot grinding on the periph-,

ery .of the work, means for retracting the work from the grinding wheel at the conclusion of the grinding operation including a cam for retracting the yieldable contacting roll, and a coupling between the contacting roll and flexible drive whereby the work is retracted from the grinding wheel and relative to the work supporting member.

8. In a grinding machine of the class described, the combination of a bed, a grinding wheel rotatably mounted on the bed, a work supporting member adjacent the grinding wheel for periphe erally supporting the work, flexible driving means for rotating the work on the supporting member,

yieldably actuated means including a work contacting roll for urging the work into engagement with the supporting member and grinding wheel, means limiting the movement of the work in the direction of the grinding wheel, means for periodically shifting the work from the grinding wheel to efiect spot grinding on the periphery of the work, means for retracting the work from the grinding wheel at the conclusion of the grinding operation including a cam for retracting the yieldable contacting roll, a coupling between the contacting roll ,and flexible drive whereby the work is retracted from the grinding wheel and relative to the work supporting member, and a manually actuable lever for actuating the retract- 76 ing means.

yieldingly urging the work toward the grinding wheel, means for limiting the urge of the work toward the grinding wheel, means .for periodically actuating the work from the grinding wheel, and power means for actuating the work limiting and retracting means comprising an hyraulic cylinder, a piston therein and actuable relative thereto, an oscillatable cam, and a rack and pinion connection between the piston and cam.

10. In a grinding machine of the class described, the combination of a bed, a grinding wheel rotatably mounted thereon, a work support adjacent the grinding wheel, means for positively rotating 9, work piece while on the support, means for yieldingly urging the work toward the grinding wheel, means for limiting the urge of the work toward the grinding wheel, means for periodically actuating the work from the grinding wheel, power means for actuating the work limiting and-retracting means comprising an hydraulic cylinder, a piston therein and actuable relative thereto, an oscillatable cam, a rack and pinion connection between the piston and cam, a valve controlling the flow of hydraulic medium to the cylinder, a manually actuable lever for actuating the valve in one direction, moans yieldingly holding the valve in its manually actuated position, and power means for releasing the valve and shifting it to its reverse position after a definite cycle of grinding.

11. In a machine for grinding a portion of a work piece to non-circular contour in predeterperipheral portion of the work piece, means toeffect rotation of the work piece, means for urging the work piece against said supporting device as a guide, and means for effecting an oscillation of the work piece and its supporting device in a direction toward and from the grinding wheel in timed relation with the rotation of the work.

12. In a grinding machine of the character described, the combination with the grinding wheel, of work supporting members spanning the grinding wheel adjacent the operative portion of the periphery thereof whereby said members will engage pre-formed peripheral portions of a work piece, means for supporting a work piece with its periphery engaging said members and its intermediate portion in opposition to the grinding wheel, meansfor rotating the work piece at a prescribed rate while so supported, and means for efiecting a back and forth movement of the work supporting members during each rotation of the work piece whereby a central portion of non-circular contour will be formed on the work piece in predetermined relation to the pre-formed support engaging peripheral portions-thereof.

13. A grinding machine of the character described, including a grinding wheel, a work support and a work limiting mechanism disposed adjacent the grinding wheel for engagement with the work piece for positioning a work piece in operative relation to the grinding wheel, means interengaged with the work for effecting a positive rotation thereof when so supported, means for resiliently urgingthe work in the direction of the grinding wheel and the limiting devices,

means for retracting said resilient urging device, and means for subsequently jointly retracting the work and its driving means with respect to the work limiting means whereby discharge of a com-'- pleted work piece is facilitated.

14. A grinding machine of the character described including a grinding wheel, a work support and a work limiting mechanism disposed adjacent the grinding wheel for engagement with the work piece for positioning a work piece in operative relation to the grinding wheel, means inter-engaged with the work for efiecting a positive rotation thereof when so supported, means for resiliently urging the work in the direction of the grinding wheel and the limiting devices, means for retracting said resilient urging device,

means for subsequently jointly retracting the.

7 thereof.

15. A grinding machine of the character described including a grinding wheel, means adjacent the grinding wheel adapted to peripherally engage and support a work piece in operative relation to the grindingwheel, means for effecting rotation of the work piece, means for resiliently urging the rotated work piece into operative engagement with the grinding wheel, means engageable with the work piece for variably de- A termining its position with respect to the grinding wheel whereby a. non-circular contour is produced on the work piece during rotation thereof, and a single control device for determining the operative effect of said several means as respects the work piece.

16. A grinding machine of the character described including a rotatable grinding wheel and a work support adjacent the grinding wheel for peripheral engagement with the work piece, means independent of the supportfor effecting a positive rotation of the work piece, work piece engaging means for limiting the movement of the work piece .inithe direction of the grinding wheel, means for shifting said limiting means and thus the work in a direction substantially radial with respect to the grinding wheel at its the workpiece diameter as produced by the grinding wheel, a-driving member, connections between the driving member and the work'ro- 1 tating mechanism for eifecting power rotation thereof, connections between the driving inem- 'ber and the limiting devices for effecting their movement. and a single clutch effective to deterscribed including a rotatable grinding wheel and a work support adjacent the grinding wheel for peripheral engagement with the work piece,

. means independent of the support for effecting point of contact with the work whereby to vary a positive rotation of the work piece, work piece eng ng means for limiting. the movement of the work piece in the direction of the grinding wheel, means for shifting said limiting means and thus the work in a direction substantially radial with respect to the grinding wheel at its point of contact with the work whereby to vary the work piece diameter as produced by the grinding wheel, a driving member, connections between the driving member and the work rotating mechanism for effecting power rotation thereof, connections between the driving member and the limiting devices for effecting their movement, a single clutch effective to determine the operative connection between the driving mem-' ber and sa id work rotating and position determining elements, means for resiliently urging the work piece in the direction of the grinding wheel, and a single control device coupled with said resilient means and said clutch for determining the operative positionings thereof.

18. A- grinding machine of the centerless type including a grinding wheel and an opposed carriage, a bracket pivoted to the carriage in proximate relation to the grinding wheel, aplurality of work supporting 'members carried by the bracket for determining the position of a work piece on the bracket, means for rotating the work piece and urging the same in the direction of the grindingwheel, and power driven means for effecting a limited oscillatory movement of the bracket and parts carried thereby during rotation of the work piece whereby the periphery of the work piece will be variably presented to the operative face of the grinding wheel substantially 'as and for the purpose described.

GEORGE W. BINNS. 

